Earth science 5.2
Transcript of Earth science 5.2
5.2 Soil
Regolith
• The layer of rock and mineral fragments that nearly everywhere covers Earth’s surface
Soil
• A combination of mineral and organic matter, water, and air.
Soil Horizon
• A layer of soil that has identifiable characteristics produced by chemical weathering and other soil-forming processes
Soil Profile
• A vertical section through a soil showing its succession of horizons and the underlying parent material.
Pedalfer
• Soil of humid regions characterized by the accumulation of iron oxides and aluminum- rich clays in the B horizons.
pedocal
• Soil associated with drier regions and characterized by an accumulation of calcium carbonate in the upper horizons
laterite
• A red, highly leached soil type found in the tropics that is rich in oxides of iron and aluminum.
Key Concept
• Soil is the part of the regolith that supports the growth of plants
Key Concept
• Soil has four major components: mineral matter, or broken-down rock; organic matter, or humus, which is the decayed remains of organisms; water; and air.
Key Concept
• The most important factors in soil formation are parent material, time, climate, and slope.
Key Concept
• Soil varies in composition, texture, structure, and color at different depths.
Key Concept
• Three common types of soil are pedalfer, pedocal, and laterite.
Key Concept
• However, human activities that remove natural vegetation, such as farming, logging, and construction, have greatly accelerated erosion.